The proposed research will investigate the metabolism, structure and function of lipids in membranes and other natural and model lipoproteins, and will investigate the metabolism and occurrence of natural alkylphosphonates both in mammals and lower invertebrates. Studies on the bacterium Lactobacillus plantarum will seek to determine the role of changes in membrane enzyme levels in the synthesis and degradation of membrane lipids, while P31 nuclear magnetic resonance spectroscopy will be used to investigate the interactions of lipids and proteins in biological preparations such as membranes and serum lipoproteins. The metabolism of 2-aminoethylphosphonate by the rat and the anemone Metridium dianthus will continue to be studied so that we may determine better how the human metabolizes this coumpound which occurs rather widely n human food sources as clams, oysters, and ruminant tissues. BIBLIOGRAPHIC REFERENCES: P31 nuclear magnetic resonance studies on serum low- and high-density lipoprotein, T.O. Henderson, A.W. Kruski, L.G. Davis, T. Glonek, and A. M. Scanu., Biochemistry 14, 1915-1920 (1975) . Effect of inhibition of protein synthesis on lipid metabolism in Lactobacillus plantarum. L.Y. Argogast and T.O. Henderson, J. Bacteriol. 123, 162-171 (1975).